PITTSBURGH — Any expectations that for the fourth time in five years the Rangers would make a deep playoff run were decisively swept away on Saturday.

That’s when the Penguins shredded the flailing Blueshirts, 6-3, sending them into an early offseason for the first time since 2011 by eliminating them in five games in the first round of the Stanley Cup playoffs.

There was no stopping the sizzling Penguins, who scored five consecutive goals in a rocking CONSOL Energy Center to erase a 2-1 first-period deficit.

“We didn’t have answers for anything,” said Derrick Brassard. “Brutal way to lose.”

It was a particularly ugly end to the season for the Rangers, with Henrik Lundqvist abandoned in the second period, as the Penguins cashed in on odd-man rushes. By the end of the period, the team’s MVP had allowed 10 goals in the last five periods — four in the 5-0 blowout in Game 4 at Madison Square Garden and six on 22 shots in the season-ending matinee, before being mercifully yanked for Antti Raanta at the start of the third period.

“It was a feeling of embarrassment to give up that many goals, but also a sense of hopelessness, not being able to come up with saves and the score [6-2] being the score in the second period, definitely not a good feeling,” said Lundqvist.

A somber coach Alain Vigneault thought the series tilted in favor of the Penguins in the third game, with the series tied at 1.

With a 1-0 lead, he said, “the turning point was a penalty [on Marc Staal] we took at the end of the second period, and they capitalized on that [with Sidney Crosby’s power-play goal]. Then they score on a flip out when two of my defensemen [Dan Boyle and Keith Yandle] run into each other [and Matt Cullen scored for a 2-1 lead in the third]. It changed the dynamics of the series. And after that we didn’t play well in the fourth game.”

On Saturday, the Rangers actually scored first. A floater from the point by Dan Girardi, playing for the first time since Game 1, was deflected in by Rick Nash at 1:02, his second goal of the series.

But former Ranger Carl Hagelin got behind Derek Stepan and finished a feed from Phil Kessel on the doorstep at 9:50. Forty-five seconds later, the Blueshirts went ahead when Viktor Stalberg’s shot hit the post and Dom Moore trickled the puck through Matt Murray, who was in goal for the past three wins.

But with Brady Skjei in the box for boarding, the Penguins vaunted power-play struck for its eighth goal of the series. Kessel’s pinpoint wrister from the right dot went high inside the far post at 11:39 to make it 2-2.

Vigneault had dressed 11 forwards and seven defensemen, a tactic that he had deployed in Game 7 of the playoffs against Tampa last year when Ryan McDonagh dressed with a broken bone in his foot and again on Feb. 29 this year. That strategy backfired, as both the Penguins veterans and youngsters contributed to the rout.

At 5:21 of the second, defenseman Trevor Daley wound up for a slap shot from the slot, the Rangers froze, and but he found rookie Bryan Rust open at the right post for a gimme as the Penguins took a 3-2 lead. Lundqvist had no chance, but was serenaded with a mocking “Hen-rik” chant from the crowd anyway.

They were even louder when Brassard was stripped from behind in his own zone by Rust and followed by Cullen, who beat Lundqvist for a 4-2 lead at 9:26, as the Blueshirts continued to wilt and the Penguins attacked without much resistance. Crosby pulled up on a rush that started in his own zone and found Conor Sheary at 16:18, and Evgeni Malkin passed to Rust who cruised down the middle for his second at 19:01. Chris Kreider tipped a shot from Raphael Diaz on a power-play 5:38 into the third.

“We didn’t defend nearly well enough to win a playoff series,” said Marc Staal. “We were not on the same page from our blueline in for a lot of it. They were better than us all series. They beat us special teams and they were defending really well, played very simple, waiting for their opportunities, and when we would try to force things to create, they capitalized and buried it on us.”